Did you often say thank you to your mon when she helped you? Probably you said few times, or you used to say that to your mom, it depends. But the times of thank you do not stand for how much you loved her. This is a issue of culture. Of course, we usually saw foreigners say "thank you" and "sorry" as well as "I love you" in films and in real life, because they prefer to express their emotions by the straightforward way, which is one of the heart of their culture. On the contrary, for the most of the Chinese people, we are unwilling to expressing ourselves so straightforward, which is one of our culture that our forefather leaves to us. We shouldn't blame these people who don't get used to expressing their kindnesses by saying thank you. What we really should blame are those people who are good at taking helps from others for granted.